058 lean construction (part 2) construction productivity
TRANSCRIPT
LEAN CONSTRUCTION
In the past 50 years, manufacturing industries have greatly improved their competitiveness.
This has been achieved through the use of lean methods such as:
Supply Chain Management Just-In-Time techniques. Also, for several years lean methods have
been applied to the construction industry,
LEAN CONSTRUCTION
Lean construction is a process used to maximizes value and reduces waste.
Lean construction comes from Lean production.
It captures these objectives through the use of Supply Chain Management (SCM) and Just-In-Time (JIT) techniques,
Also, by sharing information between all the parties involved in the production process.
LEAN CONSTRUCTION
It is based on lean manufacturing, of the Toyota Production system. developed by Taichii Ohno in the
1950s. Ohno learnt from mass production at
Ford Motor manufacturing facilities in the U.S. and witnessed high level of waste during production.
LEAN CONSTRUCTION
Ohno identified several wastes in mass production systems in car industry such as:
1. overproducing2. waiting time 3. transporting
LEAN CONSTRUCTION
also, in other areas such as:1. processing methods; 2. unnecessary stock on hand; 3. unnecessary motion;4. defective goods; 5. failure to meet customers’ needs;6. high waste through out the
process.
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The Toyota Production System was based on the “Just –In – Time (JIT) philosophy;
The main objectives were: minimizing waste continuous improvement from
inception to completion with highly motivated work force
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The outcome was:reduced inventories High productivity better equipment
utilization of machinery shorter lead times
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Less errors Highly motivated workforce with higher morale JIT is a pull system that responds to
actual customer demand. products are “pulled from ” the JIT
system.
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JIT only considers the resources required to meet the customer’s needs.
In the mid – 1970’s Toyota reduced the time needed to produce a car from fifteen days to one day, by using JIT.
LEAN CONSTRUCTION
Applying Lean Thinking in construction Using experienced design teams The same design team working on the design
of the project from beginning to end. Speed up the design process. Use innovative approaches to speed up the
design process. Innovative ideas in design and assembly. The use of pre-fabricated building elements. Manufactured off site and pre-assembled on
site.
LEAN CONSTRUCTION
Supporting sub-contractors in developing tools for improving processes.
In order to keep up with Leanconstruction It is important to follow the work of Construction Lean Improvement Programme (CLIP).
CLIP operates across the whole construction supply chain, from raw materials processors to clients.
LEAN CONSTRUCTION
Researchers believe that project cost will increase up to ten percent because of poor supply chain design.
Supply Chain Management (SCM) analyzes the impact of design on the construction process.
Through SCM, all parties are kept aware of commitments, schedules, etc.
LEAN CONSTRUCTION
All the parties work for high quality product with minimal lead-time, including:
minimizing wastage; eliminating delays and disruptions.Ballard and Howell designed the
Last Planner System as one method for applying lean techniques to construction.
LEAN CONSTRUCTION Womack and Jones (1996) suggested
that there are five key principles that need to be monitored when lean construction systems are applied in construction. Those are:
Value-clarifying the customer’s needs; the supply chain involvement in all
stages, from inception to completion; By clarifying activities or products that signify value.
LEAN CONSTRUCTION
Value stream: By mapping thewhole value stream establishing cooperation between
all parties involved; identifying and eliminating waste; From taking such steps the
construction process can be improved.
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Flow: Business flow includes project
information such as:1. specifications 2. contracts 3. plans, etc. Job site flow involves the activities and
the way they have to be carried out. Supply flow refers to the materials
used in a project.
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Pull: The efforts of all participants
provides smooth pulls during the construction process.
Perfection: Use of best methods of work
instructions and best procedures. Introduction of best quality control
methods.
Current practice V lean construction CURRENT LEAN
Construction management is either activity or contract centred
Coordination between organizations or crews is primarily controlled from a central plan
that central plan establishes sequence and determines when an activity starts/finish
in lean production, the production is managed in a manor that the main objective is best product at lowest cost for customer
Project duration and cost are considered in “project-as-production system” terms
project total cost and duration are more important than the cost or duration of an activity
Current practice V lean construction CURRENT LEAN
costs, errors, and learning occur while work in progress
cost savings results from productivity improving
Often not achievable resulting in cost, time overrun
project duration is cut short by increasing manpower, machinery,
by adding additional activities to reduce time
Coordination is accomplished in
general by the central schedule
the details of work flow are managed throughout the organization by people who are project goals orientated
Time, cost, quality,..
LEAN CONSTRUCTION CURRENT LEAN
Additional cost due to waste
which could have been avoided within the activities,
Delays and disruption which could have been avoided within activities,
customers are valued highly,
primary objectives is the
work flow, Movement of
information, good
communication amongst all,
Movement of materials,
LEAN CONSTRUCTION CURRENT LEAN
rework which could have been avoided,
all add to total time of the project,
disrupt in critical path
Increases time and cost,
Waste control, Highly
motivated work force,
Removal of hygiene factors (de-motivating factors),
LEAN CONSTRUCTION
Lean thinking forces attention on how value is generated rather than how any one activity is managed.
An overall success.
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Just-In-Time(JIT)
Supply ChainManagement
(SCM)
Business FlowPull
Perfection
LeanConstruction
maximizes valuereduceswaste
Based on LeanManufacturing, of the Toyota
Production system
JIT onlyconsiders the
Resourcesrequired
Construction LeanImprovement Programme
(CLIP),(Supply chain)
High quality product with minimallead-time
Eliminating delays and disruptions